The invention relates to a method of preparing a material for hot briquetting and to an apparatus for carrying out the method.
A method of this kind for preparing a briquetting material is known from German Pat. Nos. 15 71 710 and 16 71 377. The methods described in these two patents relate particularly to measures aimed at the recovery of some of the crude tar from the briquetting material during the compaction. According to German Pat. No. 15 71 710, the yield of crude tar should range between 0.2 and 0.8%, and according to German Pat. No. 16 71 377,between 0.07 and 0.2%. It was primarily intended to obtain a maximum tar extraction from the briquetting material. Indicated as important features of the method are mixing temperatures of 450.degree. C. to 530.degree. C., and a dwell time of the briquetting material of 1 to 15 minutes. It has been found in this connection that what reaches the briquetting press is not always a uniformly mixed briquetting material, and that particularly the degassing and tar removal vary. Already in briquetting presses having a roll width of more than 400 mm, this drawback resulted in a reduction of the total output to less than about 7 tons per hour.